Decision making in Parkinson's disease: An analysis of the studies using the Iowa Gambling Task

Reward Circuit Local Field Potential Modulations Precede Risk Taking

Risk taking behavior is a symptom of multiple neuropsychiatric disorders and often lacks effective treatments. Reward circuitry regions including the amygdala, orbitofrontal cortex, insula, and anterior cingulate have been implicated in risk-taking by neuroimaging studies. Electrophysiological activity associated with risk taking in these regions is not well understood in humans. Further characterizing the neural signalling that underlies risk-taking may provide therapeutic insight into disorders associated with risk-taking. Eleven patients with pharmacoresistant epilepsy who underwent stereotactic electroencephalography with electrodes in the amygdala, orbitofrontal cortex, insula, and/or anterior cingulate participated. Patients participated in a gambling task where they wagered on a visible playing card being higher than a hidden card, betting $5 or $20 on this outcome, while local field potentials were recorded from implanted electrodes. We used cluster-based permutation testing to identify reward prediction error signals by comparing oscillatory power following unexpected and expected rewards. We also used cluster-based permutation testing to compare power preceding high and low bets in high-risk (<50% chance of winning) trials and two-way ANOVA with bet and risk level to identify signals associated with risky, risk averse, and optimized decisions. We used linear mixed effects models to evaluate the relationship between reward prediction error and risky decision signals across trials, and a linear regression model for associations between risky decision signal power and Barratt Impulsiveness Scale scores for each patient. Reward prediction error signals were identified in the amygdala (p=0.0066), anterior cingulate (p=0.0092), and orbitofrontal cortex (p=6.0E-4, p=4.0E-4). Risky decisions were predicted by increased oscillatory power in high-gamma frequency range during card presentation in the orbitofrontal cortex (p=0.0022), and by increased power following bet cue presentation across the theta-to-beta range in the orbitofrontal cortex ( p =0.0022), high-gamma in the anterior cingulate ( p =0.0004), and high-gamma in the insula ( p =0.0014). Risk averse decisions were predicted by decreased orbitofrontal cortex gamma power ( p =2.0E-4). Optimized decisions that maximized earnings were preceded by decreases within the theta to beta range in orbitofrontal cortex ( p =2.0E-4), broad frequencies in amygdala ( p =2.0E-4), and theta to low-gamma in insula ( p =4.0E-4). Insula risky decision power was associated with orbitofrontal cortex high-gamma reward prediction error signal ( p =0.0048) and with patient impulsivity ( p =0.00478). Our findings identify and help characterize reward circuitry activity predictive of risk-taking in humans. These findings may serve as potential biomarkers to inform the development of novel treatment strategies such as closed loop neuromodulation for disorders of risk taking.

Decision-making under ambiguity and risk and executive functions in Parkinson's disease patients: A scoping review of the studies investigating the Iowa Gambling Task and the Game of Dice

Evidence shows that patients affected by Parkinson's disease (PD) display the tendency toward making risky choices. This is due, at least in part, to the pathophysiological characteristics of the disease that affects neural areas underlying decision making (DM), in which a pivotal role is played by nonmotor corticostriatal circuits and dopamine. Executive functions (EFs), which can be impaired by PD as well, may sustain optimal choices in DM processes. However, few studies have investigated whether EFs can support PD patients to make good decisions. Adopting the scoping review approach, the present article is designed to deepen the cognitive mechanisms of DM under conditions of ambiguity and risk (that are conditions common to everyday life decisions) in PD patients without impulse control disorders. We focused our attention on the Iowa Gambling Task and the Game of Dice Task, because they are the most commonly used and reliable tasks to assess DM under ambiguity and under risk, respectively, and analyzed the performances in such tasks and their relationships with EFs tests in PD patients. The analysis supported the relationships between EFs and DM performance, especially when a higher cognitive load is required to make optimal decisions, as it happens under conditions of risk. Possible knowledge gaps and further research directions are suggested to better understand DM mechanisms in PD sustaining patients' cognitive functioning and preventing negative consequences in everyday life derived from suboptimal decisions.

Decision-making deficits in obsessive-compulsive disorder are associated with abnormality of recency and response consistency parameter in prospect valence learning model

Background

Patients with obsessive-compulsive disorder (OCD) have deficits in decision-making in the Iowa Gambling Task (IGT). However, no study has investigated the parameters of the prospect valence learning (PVL) model in the IGT for OCD.

Aims

This study aimed to investigate deficits in decision-making in OCD using the PVL model and identify whether the parameters of the PVL model were associated with obsessive-compulsive severity.

Methods

Forty-seven medication-free patients with OCD were compared with 47 healthy controls (HCs). Decision-making was measured using the total net and block net scores of the IGT. A PVL model with a decay-reinforcement learning rule (PVL-DecayRI) was used to investigate the parameters of the model. Correlation analysis was conducted between each parameter of the PVL-DecayRL and obsessive-compulsive symptoms.

Results

The total net score of patients with OCD was significantly lower than that of the HCs. The block net scores of the OCD group did not differ across the five blocks, whereas in the HCs, the fifth block net score was significantly higher than the block net scores of the first and second blocks. The values of the recency and response consistency parameters of the PVL-DecayRI in patients with OCD were significantly lower than those in HCs. The recency parameter positively correlated with the Y-BOCS obsessive score. Meanwhile, there was no correlation between consistency parameter values and symptom severity in OCD.

Conclusion

Our detailed analysis of the decision-making deficit in OCD suggests that the most recent outcome has a small influence on the expectancy of prospect valence, as indicated by the lower recency parameter, and is characterized by more impulsive choices, as indicated by the lower consistency parameter.

Decision-making abilities under risk and ambiguity in adults with traumatic brain injury: what do we know so far? A systematic review and meta-analysis

Traumatic brain injury (TBI) is a major health and socio-economic problem since it is one of the major sources of death and disability worldwide. TBI patients usually show high heterogeneity in their clinical features, including both cognitive and emotional/behavioral alterations. As it specifically concerns cognitive functioning, these patients usually show decision-making (DM) deficits. DM is commonly considered a complex and multistep process that is strictly linked to both hot and cold executive functioning and is pivotal for daily life functioning and patients' autonomy. However, the results are not always in agreement, with some studies that report huge alterations in the DM processes, while others do not. The present systematic review and meta-analysis aims to integrate past literature on this topic, providing a clear and handy picture both for researchers and clinicians. Thirteen studies addressing domain-general DM abilities were included from an initial N = 968 (from three databases). Results showed low heterogeneity between the studies (I2 = 7.90, Q (12) = 13.03, p = .37) supporting the fact that, overall, TBI patients showed lower performance in DM tasks as compared to healthy controls (k = 899, g = .48, 95% CI [0.33; 0.62]) both in tasks under ambiguity and under risk. The evidence that emerged from this meta-analysis denotes a clear deficit of DM abilities in TBI patients. However, DM tasks seemed to have good sensitivity but low specificity. A detailed description of patients' performances and the role of both bottom-up, hot executive functions and top-down control functions have been further discussed. Finally, future directions and practical implications for both researchers and clinicians have been put forward.

Gambling associated risk-taking decision in cerebellar ataxia

INTRODUCTION

People with cerebellar ataxia (CA) can develop impulsive and compulsive behaviors that significantly affect their and their family's quality of life. To further assess the decision-making process associated with these behaviors, we used the Iowa Gambling Task (IGT) to study people with CA.

METHODS

Sixty individuals with CA and thirty age-matched controls were enrolled in the study to complete the IGT. No participants had a prior or comorbid neurologic or psychiatric disorder associated with impulsivity. IGT performance in each of the five 20-trial blocks was compared between groups and the progression of participants' performance was assessed with simple linear regression models. Subgroup analyses were performed with genetic and non-genetic CA cases.

RESULTS

CA cases obtained significantly lower IGT total scores than controls (-5.30 ± 37.53 vs. 21.30 ± 37.37, p = 0.004). In addition, those with CA made riskier decisions throughout the task compared to controls. Although both CA and controls learned to make decisions with more favorable outcomes over the course of completing the IGT, CA participants never matched the controls' performance. IGT performance did not correlate with ataxia severity or depressive symptoms.

CONCLUSION

The IGT may capture a unique behavioral symptom of CA. Future studies may help elucidate the mechanisms underlying impaired decision-making in CA and further the understanding of a broader spectrum of cerebellar cognitive affective syndrome.

Aging-related changes in reward-based decision-making depend on punishment frequency: An fMRI study

Introduction

Aging is often accompanied by significant cognitive decline and altered decision making. Previous studies have found that older adults have difficulty in processing reward/risk information, leading to suboptimal decision strategy. However, it is still under investigated about the neural substrates of risky decision-making under ambiguity in aging.

Methods

Using the Iowa Gambling Task, the current study investigated inter-individual differences of risk-taking behaviors in healthy older adults with task-related functional magnetic resonance imaging.

Results

It was found that participants were able to improve their decisions in advantageous decks, but failed to avoid disadvantageous decks during task performance. The task-related activations within multiple brain regions were observed significantly different across the four decks, and showed negative correlations with age in disadvantageous decks but not in advantageous decks. Consistently, age-related whole brain analyses confirmed the negative age-effect on brain activations in disadvantageous decks, especially in high punishment frequency. In addition, the relationship between age and task performance in high punishment frequency was mediated by activation in the frontal subregions such as the middle frontal cortex and superior medial frontal cortex.

Discussion

Our findings shed light on the neural substrates of altered risk-taking behaviors in aging, suggesting a greater sensitivity to high punishment frequency in older adults.

Executive Functions in Decision Making under Ambiguity and Risk in Healthy Adults: A Scoping Review Adopting the Hot and Cold Executive Functions Perspective

Decision making (DM) has a pivotal role in supporting individual autonomy and well-being. It is considered a complex ability exploiting many cognitive functions, among which executive functions (EFs) are crucial. Few studies analyzed the role played by EFs in DM in healthy adults under ambiguity and risk, which are common conditions for most decisions in daily life. This scoping review aims to analyze the relationships between two individual tasks widely used to assess DM under these conditions (Iowa Gambling Task and Game of Dice Task) and EFs. According to the organizing principle that conceptualizes hot and cold EFs, DM under such conditions mainly implies hot EFs, but the relationship with cold EFs is still unclear. Using such an approach, a comprehensive framework is provided, highlighting main findings and identifying possible gaps in the literature. The results suggest different roles played by cold EFs in DM under ambiguity and risk, according to the characteristics of the tasks. The findings can offer guidance to further studies and to design interventions to support DM in healthy adults.

Decreased sensitivity to loss of options in patients with Parkinson's disease

Humans prefer to have many options when making decisions. When there is a threat of options disappearing, humans invest more to keep these options available, indicating that they are sensitive to the loss of options. This study examined whether patients with Parkinson's disease (PD), a disease characterized by dopamine depletion, try to keep options available when options are disappearing. Twenty-seven PD patients without dementia and 27 healthy controls (HCs) performed the door game, in which participants were presented with multiple alternatives in the form of three doors, each associated with a different point distribution. The participants were asked to maximize their point earnings by finding the best door. The task included two conditions. In the shutter condition, shutters gradually closed on doors that were not chosen; once the shutters completely closed, the door was no longer available. There were no shutters in the control condition. The results revealed that the HCs switched doors more often in the shutter condition than in the control condition, indicating a tendency to keep options available. However, the PD patients did not show such differences between the two conditions. The difference in the number of switches between the shutter and control conditions in the PD patients was significantly positively correlated with the distribution of dopamine transporters in the left striatum, as measured by ¹²³I-ioflupane-SPECT (DaTSCAN) images. These results suggest that PD patients are less sensitive to the loss of options, and this decreased sensitivity may be caused by a decline in dopaminergic neurotransmission.

Relationship between motor learning and gambling propensity in Parkinson's disease

INTRODUCTION

The basal ganglia and related dopaminergic cortical areas are important neural systems underlying motor learning and are also implicated in impulse control disorders (ICDs). Motor learning impairments and ICDs are frequently observed in Parkinson's disease (PD). Nevertheless, the relationship between motor learning ability and ICDs has not been elucidated.

METHODS

We examined the relationship between motor learning ability and gambling propensity, a possible symptom for prodromal ICDs, in PD patients. Fifty-nine PD patients without clinical ICDs and 43 normal controls (NC) were administered a visuomotor rotation perturbation task and the Iowa Gambling Task (IGT) to evaluate motor learning ability and gambling propensity, respectively. Participants also performed additional cognitive assessments and underwent brain perfusion SPECT imaging.

RESULTS

Better motor learning ability was significantly correlated with lower IGT scores, i.e., higher gambling propensity, in PD patients but not in NC. The higher scores on assessments reflecting prefrontal lobe function and well-preserved blood perfusion in prefrontal areas were correlated with lower IGT scores along with better motor learning ability.

CONCLUSIONS

Our findings suggest that better motor learning ability and higher gambling propensity are based on better prefrontal functions, which are in accordance with the theory that the prefrontal cortex is one of the common essential regions for both motor learning and ICDs.